1. Field of the Invention
The present invention generally relates to an optical imaging lens set. Specifically speaking, the present invention is directed to a shorter optical imaging lens set of six lens elements for use in mobile phones, in cameras, in tablet personal computers, in in-car cameras, or in personal digital assistants (PDA).
2. Description of the Prior Art
In recent years, the popularity of mobile phones and digital cameras makes the sizes of various portable electronic products reduce quickly, and so does those of the photography modules. The current trend of research is to develop an optical imaging lens set of a shorter length with uncompromised good quality. With the development and shrinkage of a charge coupled device (CCD) or a complementary metal oxide semiconductor element (CMOS), the optical imaging lens set installed in the photography module shrinks as well to meet the demands. However, good and necessary optical properties, such as the system aberration improvement, as well as production cost and production feasibility should be taken into consideration, too.
The specifications of portable electronic products develop quickly, so does the key component—the photography modules. In addition to taking pictures and doing video recording, they may be used to do environmental surveillance or to serve as dashboard cameras. The demand not only for better quality but also for dim light background, larger field of view and smaller lens set space is getting higher and higher so there is a need for a lens set of better image quality and smaller size.
The designing of the optical lens is not just scaling down the optical lens which has good optical performance, but also needs to consider the material characteristics and satisfy some practical requirements like assembly yield. Therefore, how to reduce the total length of a photographic device, but still maintain good optical performance under dim light background, is an important objective to research.